I've recently discovered when troubleshooting performance issues with PC games that my computer has two built in GPUs (My particular computer is the Lenovo U530 Touch for those interested - specs). This has caused numerous perfomance issues in the fact that games will use the less powerful on-board Intel HD Graphics 4400 instead of the Nvidia 730M in many cases.
I can do my research to figure out how to fix those performance issues, but I'm just curious in the first place: why does my laptop come with both of these installed at all? Wouldn't it just be better to have the more powerful one? Can/does the computer use both of them at once?